Rotational resistance cryogenic control system for chilling in a vacuum tumbler or agitator blender

Abstract

A cryogenic control system measures rotational resistance in a cryogenic food mixing machine such as a vacuum tumbler or agitator blender to determine by test the length of time it takes from the start of chilling to reach the maximum energy level T me , and the length of time it takes to chill the product to the desired forming point stiffness T f , to establish a ratio T f /T me for that product and batch size. This ratio can then be used for subsequent cycles, regardless of cryogenic flow rate, to determine the optimum product chilling point.

What is claimed as invention is: 
     
       1. A method for controlling cryogen flow in a food mixing machine driven by a drive shaft, said method comprising the steps of: providing a first measured quantity of food product into said food mixing machine;   initiating mixing of said food product in said food mixing machine by rotation of said drive shaft and delivery of liquid cryogen onto said food product in said food mixing machine, and establishing a start time therefore;   measuring the rotational resistance to said drive shaft as said food product is chilled and the viscosity of said food product is increased by said liquid cryogen until a maximum resistance is determined, and establishing an elapsed time T me  from said start time therefore;   continuing mixing of said food product and delivery of said liquid cryogen onto said food product until said food product has achieved forming point stiffness, and establishing an elapsed time T f  from said start time therefore;   subsequently operating said food mixing machine for a second measured quantity of food product generally equal to said first measured quantity;   measuring the rotational resistance to said drive shaft as said second measured quantity of food product is chilled by said liquid cryogen until a maximum resistance is determined, and establishing an elapsed time T me2  therefore; and   continuing mixing and chilling of said second measured quantity of food product for a total elapsed time T f2  =T me2  ×T f  /T me .   
     
     
       2. The method for controlling cryogen flow in a food mixing machine of claim 1 further including the step of mathematically averaging said rotational resistance measurements to define a smooth curve. 
     
     
       3. The method for controlling cryogen flow in a food mixing machine of claim 1 wherein said step of delivering liquid cryogen into said food product comprises cycling such delivery to achieve maximum efficient chilling of said food product. 
     
     
       4. The method for controlling cryogen flow in a food mixing machine of claim 1 wherein said food mixing machine comprises a vacuum tumbler. 
     
     
       5. The method for controlling cryogen flow in a food mixing machine of claim 1 wherein said food mixing machine comprises an agitator blender.